MEAT PRODUCTION
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QUALITY
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is known as Dark, Firm, Dry (DFD) meat. An additional problem with this type of meat is that it is more susceptible to spoiling since it lacks the lactic acid which normally helps retard growth of microorganisms. At the other extreme, if there was a great lactic acid build-up before slaughter, the pH of the meat declines too quickly after slaughter and a Pale, Soft, Exudative (PSE) condition may develop. As suggested by the name, the affected meat is pale, soft, and fluid may drip from the surface. The following are some of the major pre-slaughter factors resulting in stress and subsequent poor meat quality. Distance and conditions of travel to the abattoir: Traveling long distances exerts substantial stress on animals which could lead to greatly reduced glycogen levels. Nutrition and fasting: The rate of glycogen repletion is particularly slow in animals that have been on poor quality diets and/or that have been fasted long periods prior to slaughter. Mixing strange animals prior to transportation or slaughter: This can lead to fighting while establishing a new social order. Physical activity: Too much physical exertion prior to transport or slaughter can increase stress. Transportation-related problems and precautions: These include the following: • Loading and unloading are often the most stressful parts of the transport process and it is imperative that
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proper thought and planning be given to the procedure to avoid using excessive force. For instance, one of the most common mishandling practices involves deep and extensive bruising along the back of the animals caused by lifting the live animal by the hair or wool. If the sheep must be lifted during the loading and unloading operations, the workman should embrace the lamb by extending both arms through the flank region under the body. When caught from the rear they should always be grasped by the hind leg and never by the wool. Animals should not be overcrowded. This helps prevent injury and unnecessary suffering. The journey should be made in a careful manner avoiding sudden stops and starts, fast-turning and unnecessary delays. Lambs and kids may travel for 9 hours before a minimum rest period of 1 hour followed by a further maximum of 9 hours. Adult sheep and goats may travel for 14 hours before a minimum rest period of 1 hour, followed by a further maximum of 14-hours travel. Feed and water should be available during the rest periods. Animals normally lose weight during transport. It is possible in many cases to restore some, if not all, of this loss with adequate rest. In South Africa, the resting of adult Merino sheep for 24 hours with feed and water after rail transport for more than 3 days had beneficial effects on carcass yield.
12.5.1. Animal husbandry in the lairage Minimizing stress in the period immediately before slaughter is important for economic reasons related to meat quality as well as for animal welfare. Animals must be handled carefully at all times with minimal use of force. • Most lairages in the abattoir should have solid non-slip floors suitably sloped for adequate drainage. They
must be well-lit and ventilated. During the pre-slaughter period in the lairage, animals must be kept under conditions which prevent any further contamination of feet, hides, fleeces or skins. • The attitude of the attendant in the abattoir can be all-important to the calm and efficient operation of the facility. Persons experienced in animal husbandry know instinctively where to stand when moving stock and can carry out their task using only encouraging noises and the occasional tap or wave of a stick. Sheep and goat production handbook for Ethiopia